prettier checkboxes for README

Because GitHub won't fix https://github.com/github/markup/issues/208 :(
Merge pull request #16 from cvan/patch-1

prettier checkboxes for README
Add styleguide deps
Add styleguide (bug 970451)
Merge pull request #14 from muffinresearch/styleguide

Add styleguide (bug 970451)
Add casper test infra (981054)